| 摘要 |
<p>The invention relates to a zoom lens, a camera and a portable information terminal device and aims to provide a high-performance small-sized zoom lens. The lens which has the characteristics of short focal length, bright view, less-than-42-degree semi-visual angle, less-than-2.4 F value, and more than fourfold zoom ratio has a resolving power corresponding to camera elements with 10000 to 15000 thousand pixels. The lens is provided with four lens groups (G1)-(G4) from a shot body side and sequentially having a positive, negative, positive, and positive reflecting capability. Diaphragms (S) are equipped between (G1) and (G3). When the zooming is from a short focal length to a long focal length, then the space between the (G1) and (G2) and the space between (G3) and (G4) are increasing while the space between (G2) and (G3) is decreasing. (G1) and (G3) are more adjacent to the position of the shot body when the zooming process is on the long focal length basis than that on the short focal length. Furthermore, positive lenses formed by materials satisfying certain requirements respectively act as a lens closest to the shot body and a lens closest to an imaging face.</p> |
